The invention relates to the use of intact bispecific antibodies for the induction of anti-tumor immunity in humans and animals.
Despite of the progress in chemotherapy and radiotherapy achieved in recent years, malignant diseases in humans, for example terminal breast cancer, still have an extraordinarily unfavorable prognosis. These diseases are impossible to cure. Therefore, it is necessary to develop new treatment strategies. In this respect, great hopes are placed in immunotherapeutical approaches enabling the immune system of the patient to reject the tumor. It is well-known that tumor-associated antigens exist on tumor cells and that in principle the immune system can recognize these antigens and attack the malignant cells. Tumors have, however, developed certain strategies enabling them to escape the immune reaction for example by insufficient presentation of tumor-associated antigens and/or insufficient activation of the tumor-specific T cells which are generally present.
With about 43,000 new cases/year, breast cancer occupies a top position in the cancer statistics of women in Germany. Less than one third of the women suffering from lymph node invasion at the time of diagnosis survive for 10 years without relapse.
Against this background, attempts have been made since several years towards the prolongation of life or even healing of female patients suffering from extensive lymph node invasion and distant metastases by means of autologous bone marrow and stem cell transplantation in connection with high-dose chemotherapy. Despite high response rates to the high-dose chemotherapy a permanent cure in the metastatic stage rarely occurs.
To date, immunotherapeutic approaches to the treatment of mammary carcinoma have been restricted to methods for unspecific stimulation such as the treatment with BCG or levamisole as well as the use of LAK cells and NK cells together with IL-2. There has been no evidence for a prolongation of life by the types of immunotherapy used so far, while the treatment with BCG rather turned out to be disadvantageous. Since the unspecific activation of cells has achieved little success also with other tumor types, attempts were made to raise a specific immune reaction.
For example, T cell-redirecting bispecific antibodies have been used in tumor therapy. These antibodies are able to bind to a T cell receptor complex by one binding arm and to a tumor-specific antigen on a tumor cell by the second binding arm. Due to resulting activation of the T cell and the spatial proximity of the tumor cell, the latter is killed by either by induction of apoptosis or by cytokines such as TNF-xcex1 or perforin.
It is an object of the present invention to provide a novel method for the therapy of malignant diseases in humans.
According to the invention, this object has been achieved by the features characterized in more detail below. Preferred embodiments of the invention are obvious from the dependent claims.
Thus, the invention discloses a method for the induction of an anti-tumor immunity by administering to a human or an animal subject an efficient amount of an intact bispecific or trispecific antibody or a combination thereof, having the following properties and effects of:
(a) binding to a T cell to which it mediates a first activation signal;
(b) binding to tumor-associated antigens on a tumor cell;
(c) binding, by its Fc portion (in the case of bispecific antibodies) or a third specificity (in the case of trispecific antibodies), to the Fc receptor of Fc receptor-positive cells;
(d) activation of the Fc receptor-positive cell by binding to the Fc receptor-positive cell and, thereby, initiating or increasing the expression of cytokines and/or costimulatory antigens;
(e) transfer of at least a second activation signal required for physiological activation of the T cell to the T cell by the co-stimulatory antigens and/or cytokines, this activation being indicated by up-regulation of activation markers, killing of the tumor cell, and/or T cell proliferation.
Preferably, the antibodies used in the method of the present invention are able to activate the tumor-specific T cells recognizing a tumor-specific peptide presented on the tumor cells by MHC class I and/or class II via their T cell receptor upon binding to the bispecific or trispecific antibody as described under (e).
Further, the antibodies used according to the invention are able to reactivate the tumor-specific T cells being in an anergic state. Furthermore, they are able to induce tumor-reactive complement-binding antibodies and, thus, induce a humoral immune reaction.
Binding to the T cell takes place via CD3, CD2, CD5, CD28, and/or CD44. The Fc receptor-positive cells have at least one Fcxcex3 receptor I, II, or III.
The antibody used according to the invention is able to bind to monocytes, macrophages, and/or dendritic cells being Fcxcex3 receptor I-positive cells.
The antibodies used according to the invention lead to the initiation or increase of the expression of CD40, CD80, CD86, ICAM-1, and/or LFA-3 being co-stimulatory antigens and/or secretion of cytokines by the Fc receptor-positive cell. Preferably, the cytokines are IL-1, IL-2, IL-4, IL-6, IL-8, IL-12, and/or TNF-xcex1.
Preferably, binding to the T cell takes place via the T cell receptor complex of the T cell.
The bispecific antibody used in the invention preferably is an anti-CD3 X anti-tumor-associated antigen antibody and/or anti-CD2 X anti-tumor-associated antigen antibody and/or anti-CD5 X anti-tumor-associated antigen antibody and/or anti-CD28 X anti-tumor-associated antigen antibody and/or anti-CD44 X anti-tumor-associated antigen antibody.
The trispecific antibody used according to the invention preferably is an anti-CD3 X anti-tumor-associated antigen antibody and/or anti-CD2 X anti-tumor-associated antigen antibody and/or anti-CD5 X anti-tumor-associated antigen antibody and/or anti-CD28 X anti-tumor-associated antigen antibody and/or anti-CD44 X anti-tumor-associated antigen antibody having an additional anti-Fc receptor binding arm.
Regarding feature (a), the first signal is for example transduced via the T cell receptor complex of the T cell and, therefore, may itself lead to an unphysiological T cell activation. By this, the cell is anergized and unable to react to T cell receptor-mediated stimuli. In addition, a second activation signal is transduced simultaneously to the T cell by the bispecific or trispecific antibodies of the invention via the co-stimulatory antigens on the Fc receptor-positive cell which causes physiological activation of the T cell and, subsequently, leads to killing of the tumor cell and/or proliferation of the T cell. As a further criterion for T cell activation the up-regulation of cell surface antigens such as CD2, CD25, and/or CD28, and/or the secretion of cytokines such as IL-2 may be used.
Thus, by the use of the bsAb described according to the invention T cells are activated and retargeted against the tumor cells. Generally, the use of an unspecific activation of T cells has been of little success in immune therapy.
Preferred antibodies are heterologous bispecific antibodies selected of one or more of the following combinations of isotypes:
rat-IgG2b/mouse-IgG2a,
rat-IgG2b/mouse-IgG2b,
rat-IgG2b/mouse-IgG3;
rat-IgG2b/human-IgG1,
rat-IgG2b/human-IgG2,
rat-IgG2b/human-IgG3 [oriental allotype G3m(st)=binding to protein A],
rat-IgG2b/human-IgG4;
rat-IgG2b/rat-IgG2c;
mouse-IgG2a/human-IgG3 [caucasian allotypes G3m(b+g)=no binding to protein A, in the following indicated as *]
mouse-IgG2a/mouse-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
mouse-IgG2a/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
mouse-IgG2a/human-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
mouse-[VH-CH1, VL-CL]-human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
mouse-[VH-CH1, VL-CL]-human-IgG4/rat-[VH-CH1, VL-CL]-human-IgG4-[hinge]-human-IgG4 [N-terminal region of CH2]-human-IgG3*[C-terminal region of CH2: greater than aa position 251]-human-IgG3*[CH3]
rat-IgG2b/mouse-[VH-CH1, VL-CL]-human-IgG1-[hinge-CH2-CH3]
rat-IgG2b/mouse-[VH-CH1, VL-CL]-human-IgG2-[hinge-CH2-CH3]
rat-IgG2b/mouse-[VH-CH1, VL-CL]-human-IgG3-[hinge-CH2-CH3, oriental allotype]
rat-IgG2b/mouse-[VH-CH1, VL-CL]-human-IgG4-[hinge-CH2-CH3]
human-IgG1/human-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG4 [N-terminal region of CH2]-human-IgG3*[C-terminal region of CH2: greater than aa position 251]-human-IgG3*[CH3]
human-IgG1/mouse-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG4 [N-terminal region of CH2]-human-IgG3*[C-terminal region of CH2: greater than aa position 251]-human-IgG3*[CH3]
human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG2 [N-terminal region of CH2]-human-IgG3*[C-terminal region of CH2: greater than aa position 251]-human-IgG3*[CH3]
human-IgG1/mouse-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG2 [N-terminal region of CH2]-human-IgG3*[C-terminal region of CH2: greater than aa position 251]-human-IgG3*[CH3]
human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
human-IgG1/mouse-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
human-IgG2/human-[VH-CH1, VL-CL]-human-IgG2-[hinge]-human-IgG3*-[CH2-CH3]
human-IgG4/human-[VH-CH1, VL-CL]-human-IgG4-[hinge]-human-IgG3*-[CH2-CH3]
human-IgG4/human-[VH-CH1, VL-CL]-human-IgG4-[hinge]-human-IgG4 [N-terminal region of CH2]-human-IgG3*[C-terminal region of CH2: greater than aa position 251]-human-IgG3*[CH3]
mouse-IgG2b/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
mouse-IgG2b/human-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]
mouse-IgG2b/mouse-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3]